Dear colleague,

THE CALCULATION:
I have been computing the metal-oxide structure TeW6O24 (D3d symmetry),
with the BP86 functional, a TZP basis set (basis IV in ADF) and the ZORA
package for the core electrons. The core electrons contain all the
non-valence shells, although a test with less core electrons for
tungsten was carried out unsuccessfully.

THE PROBLEM:
Whereas the homologous compound with molybdenum converges properly,
serious problems are detected with the tungstate. There is a WARNING at
the end of the SCF procedure, in which a BAD FIT message shows that the
number of expected electrons and the numerical integration of the
density differ by more than 18 units. This problem could be related to
the auxiliary basis, but we don't know how to overcome this. In addition
of the unproper SCF-convergence, of course the geometry optimisation is
unaffordable. Geometry steps behave rarely, with very strong energy
changes in successive steps.

We normally deal with very good fits in similar calculations, so we
don't have an idea of the true problem here. I will thank any advice to
solve the problem.

Thanks

Xavi
Received on 2002-12-12 13:26:33